Turbine shroud fastening



Fms. I N,

April 6, 1943. J. A. DAVIES 2,315,601

TURBINE SHROUD FASTENING Filed Jan. 24, 1942 I I l8 a a 5 1a lNVENTOR WITNESSES:

' x/m James H. DnviEs.

, BY wvafinwv'.

ATTORNEY Patented Apr. 6, 1943 TURBINE SHROUD FASTENING James A. Davies, Media, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsyl- Vania Application January 24, 1942, Serial No. 428,022

1 Claim.

The invention relates to turbine blading of the shrouded type, more particularly to blading having integral shroud elements, and it has for its object to connect the blades in groups by segmental band or tie elements, which, with the shroud elements, are so formed as to minimize steam leakage across the blade row.

This and other objects are effected by the invention as will be apparent from the following description and claims taken in connection with the accompanying drawing, forming a part of this application, in which:

Fig. 1 is a fragmentary view showing a rotor carrying a row of blades having the improved shroud construction with portions of the latter and of the blades shown in section;

Fig. 2 is a fragmentary plan view looking down on the shroud structure of Fig. 1;

Fig. 3 is a sectional view taken along the line IIIIII of Fig. 1;

Fig. 4 is a detail sectional view of the shroud construction; and

Figs. 5 and 6 are isometric views of blade and shroud elements.

In the drawing, there is shown a row of blades l 0 carried by the rotor or disk I I.

Each blade has a root element l2, a blade element l3 and a shroud element It, and the root and shroud elements of successive blades are in contiguous relation, as shown.

Tenons or rivets l5 are formed integrally with the shroud elements I4 and extend outwardly therefrom through openings 16 provided in the shroud strips or tie bands H and the outer ends of the tenons or rivets are riveted or headed, as z.

shown at I8, to fasten the shroud strips or tie band segments in place with respect to the blades.

After a row of blades is assembled, the rotor or disk is placed in a lathe and cylindrical surfaces 20 coaxial with the rotor are machined on the shroud elements It, such surfaces facing outwardly and being disposed at either side of the shroud construction. Machining to provide the cylindrical surfaces leaves a circumferential rib 2 l.

The shroud strip segments or bands are of channel section, the sides having bearing surfaces 22 fitting the cylindrical surfaces 20 and the channel space 23 defining clearance with respect to the rib 2|.

From the structure described, it will be apparent that the shroud structure is relatively steam tight transversely of the blade row. Furthermore, it is of such a character that either axial or radial sealing strips may be associated therewith. For example, in Fig. 3 there is shown a housing or cylinder element 24 provided with sealing strips 25 whose inner edges cooperate with the outer surfaces of the shroud segments or tie bands I! to effect sealing.

While the invention has been shown in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and it is desired. therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claim.

What is claimed is:

In a turbine, a row of blades; each blade having an integral shroud element and the shroud elements being arranged circumferentially in endto-end relation; rivets or tenons extending outwardly from the shroud elements and formed integrally with the blades; the shroud elements of the assembled row having cylindrical surfaces disposed at either side of circumferentially-extend ing rib elements from which the rivets or tenons extend outwardly; and shroud strips of chann l form having the sides thereof fitting said cylindrical surfaces and having their channel spaces extending over the rib elements so as to define clearance with respect to the latter; said shroud strips having openings formed therein and through which the rivets or tenons extend and said rivets or tenons having heads cooperating with the shroud strips for holding the latter in place with their sides fitting the shroud element cylindrical surfaces tightly.

JAMES A. DAVIES. 

